The present invention relates generally to dry cleaning processes and, more particularly, to methods of removing particulate debris, including dust mites and mite fecal material from non-washable items, using materials composed of fibers that have been treated in a manner such that they acquire a long-lasting electrostatic charge of any polarity, or comprised of fibers that are charged electrostatically negative, or are capable of attaining a negative electrostatic charge with moderate agitation and friction, as with the tumbling agitation of an automatic clothes dryer.
Most household products collect airborne particles, i.e. common household dust, and other soils. Common household dust provides the living and breeding environment for numerous living species, including Dermatophagoides Pteronyssinus, i.e., the house dust mite. Dust provides the carrier medium for dust mites and their fecal material. Dust mite fecal material is the carrier particle for the Der P1 antigen, a potent allergen implicated in initiating and aggravating numerous allergic reactions ranging from contact dermatitis to more serious atopic diseases such as allergic asthma.
Many common household items composed of domestic fabrics are not washable, either because of material composition, bulk or other factors. Examples of such items include stuffed toys, pillows, throw rugs and non-washable clothing.
Stuffed toys pose a particular hazard to children, as allergy-related illnesses have increased dramatically in the past several decades, and early exposure to allergenic antigens increases the risk of developing allergic diseases at some stage of life.
Accordingly, an object of the present invention is to remove dust, as well as dust mites and other micro-organisms that live and breed in household dust, dust mite fecal material and other micro-organism excrement, and various particulate soils from fabric surfaces.
Another object is to remove various types of soil from fabric articles in a conventional automatic clothes dryer.
Still another object is to remove dust mites and mite fecal material from stuffed animals or figures in an inexpensive process that can be practiced at home.
Yet a further object is to remove dust mites and other forms of soil from fabric articles such as stuffed animals utilizing electrically charged sheets in a conventional automatic clothes dryer.
The present invention is a method of cleaning a surface of at least one fabric article, comprising the steps of placing a soiled one of the fabric articles in a chamber, together with an electrically charged material having either a permanent electrostatic charge, or a long-lasting charge, or an electronegative charge acquired during movement, or a charged material having a mixed charge, and then moving the chamber to impart motion to the fabric article and enable the material to electrically attract particulates from the article.
In the preferred embodiment, the electrostatically charged material is a non-woven webbing comprised of electret fibers, in sheet form, that is tossed loose into the drum of a clothes dryer, together with one or more preferably dry fabric articles to be cleaned. The articles may be one or more stuffed toys, pillows, throw rugs or other non-washable fabric items. The articles may also be washable items that were previously washed and now deposited into the dryer in wet condition. The drum of the clothes dryer is operated under conventional usage conditions involving rotation of the dryer drum and preferably, but not necessarily, the introduction of hot air into the drum. The attraction and trapping of dust, mites, mite fecal material and/or other particulates is accomplished by dryer tumbling and/or frictional agitation or the combined action thereof, which mechanically dislodges some of the particulates, and the repetitive frictional contact of the sheet against the objects being cleaned. The sheet of electret then acts as an electostatic trap to attract and retain the dislodged particles.
The use of electrostatically negative charged electret fibers is of particular advantage for the trapping of dust mite fecal material, while negative, positive and mixed electret fibers are efficient at trapping dust and other particulates. Electret has been demonstrated to be at least two-fold more efficient for dust attraction and retention than comparable non-electret fibers and, under optimal conditions, more than ten-fold more efficient.
The feature of removing dust mite fecal material from stuffed animals and other fabric articles advantageously provides an effective and simple method of mitigating antigens that have been demonstrated to induce, trigger and exacerbate allergic asthma in some children and infants. The method can be practiced at home simply by placing one or more stuffed animals in the drum of a conventional clothes dryer together with a sheet of electret material and then operating the dryer in a conventional manner. The dryer may be operated using air of the ambient temperature, or heated air can be introduced either prior to, or concurrent with, the placement of the electret sheet into the dryer drum. The advantage of using heated air is that exposure of dust mites to temperatures of at least 55 degrees C. for at least 15 minutes kills the mites and their eggs. The introduction of the electret sheet after heating the fabric items has the advantage of reducing the amount of charge leakage that can sometimes occur with electret exposure to heat and eliminate the possibility of softening the electret fibers.
Although the use of sheets of material containing electret fiber is the preferred choice as disclosed in the preferred embodiment, it is also possible to practice the invention and achieve the benefits thereof using other types of electrically charged materials. Another preferred embodiment is to use material composed of fibers that have an intrinsic negative electrostatic charge, or are capable of developing an electrostatic negative charge in an environment of moderate agitation (i.e., the operating dryer drum). Fibers having an intrinsic or acquired electronegative charge are then capable of attracting particulates that have a positive charge with respect to these fibers. These fibers would act as an attractant for dust and particulates, and would be especially effective as an attractant and trap for dust mite fecal material.
Another embodiment of the present invention is a sheet of at least two (2) types of fibers, with one of the fiber types being more electronegative than the other type within the triboelectric series. Such fibers (e.g., electret) would have either an intrinsic voltage difference between them, or would develop such a voltage differential in the operating environment of the dryer. The voltage differential in the microenvironment of the fiber matrix would facilitate the electrostatic trapping of particles charging either positive or negative against either of the fiber types.
It is also within the scope of the present invention, in yet a further embodiment, to provide a method of cleaning a surface of at least one fabric article comprising the steps of placing a soiled one of the articles in a drum of a conventional automatic clothes dryer and then placing an electrostatically charged material of any of the types described above in a lint trap located in an air passage between the drum and outside atmosphere. The dryer is then operated by rotating the drum in a conventional manner. This enables the soil discharged from the at least one fabric article to be carried in the air efflux through the electrically charged material in the lint trap so as to enable the dislodged soil to be electrically attracted and trapped within the charged material.
It is also within the scope of this invention to use electret material for dusting by moving the electret relative to and in contact with a surface being dusted.
Still other objects and advantages of the present invention will become readily apparent to those skilled in this art from the following detailed description, wherein only the preferred embodiments of the invention are shown and described, simply by way of illustration of the best mode contemplated of carrying out the invention. As will be realized, the invention is capable of other and different embodiments, and its several details are capable of modifications in various obvious respects, all without departing from the invention. Accordingly, the description is to be regarded as illustrative in nature, and not as restrictive.